In brake boosters of which U.S. Pat. Nos. 6,959,637, 6,896,337 and 5,761,983 are considered to be typical have an output push rod through which an operational force is transmitted to a master cylinder to effect a brake application. The output push rod is a solid shaft with a threaded adjustment screw attached thereto to set a desired spaceial relationship between pistons in the master control and movable wall in the brake booster to coordinate the actuation of the master cylinder with the input from a brake pedal to effect a brake application.
The output push rods function in an adequate manner in such brake booster but do require certain processing in their manufacture and because of being cast from as a solid member may weigh more than is necessary in order to transmit a braking force from the booster to a piston in a master cylinder.